1. Field of the Invention
This invention relates in general to devices that control electric power flow. In particular to such devices that are computer controlled.
2. Description of Prior Art
A computer controlled power strip was needed on Dec. 31, 1988. At that occasion a quick and easy means for programmed activation or deactivation of electrical lights and appliances was wanted. It was to be used for setting up a show to entertain and signal the beginning of the New Year. Over time this idea evolved, it was realized that the same computer that is used to process information also could be used to carry out the chore of turning on and off the equipment around it. Not that it is difficult to push a power switch on the equipment (e.g., printer) to be used, it is that pushing it distracts us or we often just forget to do it. There had to be a better way of managing this. For the following year's end a prototype was used to set up a show and, upon noticing that such product was still unrealized, a decision was made to develop and patent this invention expressed in it's present preferred form.
The term "Computer Assisted" is used in the title because a computer is to be the main actuator in lieu of the human operator using any of the user switches. But also any other device capable of sending an appropriate logic signal, like the one generated by the hand at the switch, has the ability to operate it's power switching action. And it is this flexible, easily controlled switching action that allows us to manage the flow of electric power to any device connected to an outlet of this apparatus.
The term "Printer" is meant to include any device that interfaces it's signals with a computer's port in the same way.
In order to provide background information so that the invention may be completely understood and appreciated in its proper context, reference may be made to a number of prior patents and known art as follows:
The Heaston U.S. Pat. No. 4,685,023 discloses a "POWER LATCH CIRCUIT FOR COMPUTER SELF DEACTIVATION" that does only that. It has no provisions to switch on or off any other device besides the computer controlling it.
There are some computers (e.g., Macintosh, Apple Computer Inc.) that can be programmed to power off or on. This feature is used for controlling the power to the computer only, possibly in conjunction with above cited power latch, and therefore are limited in the same way. My invention is able to switch on or off electrical power to any connected device and, if the computer happens to be a connected device, also will allow self deactivation.
I also have recent knowledge of a product by Laverty Systems, Inc. of Charlottesville, Va. ( 1-800-879-7693). It has some similarities with one embodiment of my invention: manual and computer control, the sharing of the port with another device and telephone line activation, but, again naming a few, does not provide: computer control to turn on the outlet, independent control of the outlet connectors, reporting to the user or software the status of the outlet, automatic power on and off for a printer, etc.
The Mione U.S. Pat. No. 4,675,537 discloses a "CURRENT CONTROLLED ON/OFF POWER LINE SWITCHING OF ELECTRICAL DEVICES" Although intended to switch on or off the flow of electric power to other devices, it does not allow independent control of the output terminals (power outlets' connectors) nor does it allow for computer control of them.
The Naimer U.S. Pat. Nos. 4,368,394 and 4,623,967 disclose "A COMPUTER-CONTROLLED SWITCHING APPARATUS for controlling power switching elements, wherein a microprocessor is connected by way of analog-digital converter means to at least one sensor for detecting the current consumption of the apparatus to be monitored, . . ." These two inventions were conceived and designed primarily for a programmed management of power, specifically to handle the unattended protection of the device being monitored and not for the off/on switching of the power to the device. My invention allows immediate management of the power, through user switches or other device (e.g., a telephone ring signal), and also said programmed management, by signals from the computer or other device (e.g., a timer alarm), to switch on or off the electrical power to a device.
The Greene U.S. Pat. No. 4,312,035 discloses an "APPARATUS FOR CONTROLLING ELECTRICAL POWER IN A DATA PROCESSING SYSTEM" that allows the computer to start a power up sequence or to disconnect all switches at once. It does not allow the computer to turn on or off individual switches.
The Engel et al U.S. Pat. No. 4,747,041 discloses an "AUTOMATIC POWER CONTROL SYSTEM WHICH AUTOMATICALLY ACTIVATES AND DEACTIVATES POWER TO SELECTED PERIPHERAL DEVICES BASED UPON SYSTEM REQUIREMENT" has some desirable features but, to name one, it does not have provisions for manually switching on or off power to any of the controlled devices. An example where such feature is necessary is in the case where the command source (computer) used the invention to power down itself. It could not be powered up again unless a user switch is provided in the invention to override this condition. Likewise, provisions to immediately turn off devices are necessary should a person need to turn a device(s) off at a moment's notice without resorting to pulling the plug. Also, manual operation will aid and comfort the user getting accustomed to automatic and programmed power switching.
The above cited U.S. Pat. 4,747,041, the Dye et al U.S. Pat. No. 4,204,249 and the Miller et al U.S. Pat. No. 4,484,258 disclose arrangements that use an elaborate service subsystem (computer) and a bus(es) dedicated exclusively to the task of controlling the power. With my invention there is no need for a dedicated bus because it can use the printer line of an existing computer. These results are achieved with simpler equipment and, what is more important, less cost.
The Pickert et al U.S. Pat. No. 4,794,525 discloses an "EXTERNAL INTERFACE CONTROL CIRCUITRY FOR MICROCOMPUTER SYSTEMS" that allows the activation of an external device when required by the computer but, because of it's purpose of protection, also does not allow manual operation nor implements the objects of my invention.
The Busam et al. U.S. Pat. No. 4,647,721 discloses a "TELEPHONE ACTIVATED POWER CONTROLLER" that also uses one of many outlet to detect power use and switches on the other outlets under such occurrence. This feature is very similar to the aforesaid Mione U.S. Pat. No. 4,675,537. It allows connection to a parallel port but does not share the port with a printer like my invention. It cannot give the computer information about the status of a particular outlet because most outlets are switched together. Individual outlets cannot be controlled by the computer. My invention can do everything this device does and more.
A BYTE OF POWER, Radio Electronics, November 1980 shows a power controller to be used with a parallel port of a computer. It is an implementation that cannot share the port with a printer. Furthermore, it requires two parallel ports to implement the use of an enable signal.
Whatever the precise merits, features and advantages of the above cited references, none of them achieves or fulfills the purposes of the present invention.